Squiz/ArrayDeclaration: improve handling of short lists inside a foreach

This commit improves how the `Squiz.Arrays.ArrayDeclaration` sniff
handles short lists inside a foreach and fixes a false positive.

See #527

Author: rodrigoprimo

src/Standards/Squiz/Sniffs/Arrays/ArrayDeclarationSniff.php

@@ -45,6 +45,26 @@ public function process(File $phpcsFile, $stackPtr)
     {
         $tokens = $phpcsFile->getTokens();
 
+        // Bail when handling the most common cases of a short list inside a foreach (see
+        // https://github.com/PHPCSStandards/PHP_CodeSniffer/issues/527).
+        if ($tokens[$stackPtr]['code'] === T_OPEN_SHORT_ARRAY
+            && isset($tokens[$stackPtr]['nested_parenthesis']) === true
+        ) {
+            $lastParenthesisCloser = end($tokens[$stackPtr]['nested_parenthesis']);
+            $lastParenthesisOpener = key($tokens[$stackPtr]['nested_parenthesis']);
+            reset($tokens[$stackPtr]['nested_parenthesis']);
+
+            if (isset($tokens[$lastParenthesisCloser]['parenthesis_owner']) === true
+                && $tokens[$tokens[$lastParenthesisCloser]['parenthesis_owner']]['code'] === T_FOREACH
+            ) {
+                $asKeyword = $phpcsFile->findNext(T_AS, ($lastParenthesisOpener + 1), $lastParenthesisCloser);
+
+                if ($asKeyword !== false && $asKeyword < $stackPtr) {
+                    return;
+                }
+            }
+        }
+
         if ($tokens[$stackPtr]['code'] === T_ARRAY) {
             $phpcsFile->recordMetric($stackPtr, 'Short array syntax used', 'no');
 

src/Standards/Squiz/Tests/Arrays/ArrayDeclarationUnitTest.2.inc

@@ -547,3 +547,9 @@ $newlineAfterDoubleArrow = [
                             '',
                             'height' => '',
                            ];
+
+// Sniff should ignore short lists when inside a foreach.
+// https://github.com/PHPCSStandards/PHP_CodeSniffer/issues/527
+foreach ($data as [, , $value]) {}
+foreach ($array as $k => [$v1, , $v3]) {}
+foreach ([$a ,$b] as $c) {} // Not a short list. Sniff should handle it.

src/Standards/Squiz/Tests/Arrays/ArrayDeclarationUnitTest.2.inc.fixed

@@ -583,3 +583,9 @@ $newlineAfterDoubleArrow = [
                             'width'  => '',
                             'height' => '',
                            ];
+
+// Sniff should ignore short lists when inside a foreach.
+// https://github.com/PHPCSStandards/PHP_CodeSniffer/issues/527
+foreach ($data as [, , $value]) {}
+foreach ($array as $k => [$v1, , $v3]) {}
+foreach ([$a, $b] as $c) {} // Not a short list. Sniff should handle it.

src/Standards/Squiz/Tests/Arrays/ArrayDeclarationUnitTest.php

@@ -233,6 +233,7 @@ public function getErrorList($testFile='')
                 536 => 2,
                 541 => 1,
                 546 => 1,
+                555 => 2,
             ];
         default:
             return [];